The current conventional method for fitting dental crowns, bridges, onlays and inlays, herein referred to generally as restorations, involves the dental practitioner sliding colored carbon paper, of which the thickness is the recommended measured distance between teeth, between the interproximal area of the tooth and the restoration. The carbon paper marks with carbon ink the proximal contact area where the two surfaces of the teeth and/or restoration are too close, and then the practitioner grinds the restoration with a rotary instrument to remove excess material. This method is tedious, inefficient, and inexact. The dental practitioner has to continually remove the restoration and grind the heavy proximal contact surface until the fitting surface and shape is achieved, at which point the restoration may be permanently fixed. It is a time consuming process and there is possibility of over-grinding, in which case a new restoration must be reconstructed to replace it. This involves significant expense of time and money, not to mention inconvenience for the patient who suffers for the delay and agony.
Another method employed is the stand alone use of a metal filing strip coated with some superfine abrasive material. The metal filing strip is inserted between the interproximal area to file down the proximal contact area of the crown for an accurate fit. Since the space between the tooth and the crown, bridge, onlay, and inlay must not be too close nor too spaced apart the practitioner must file incrementally. These steps are repeated until the desired distance between the tooth and the restoration is achieved. Because the filing strip is extremely thin, narrow, and malleable, it is necessary for the practitioner to maintain tension in the strip by holding it taunt at opposite ends with fingers from both hands. Unfortunately holding the filing strip in such as manner is cumbersome in the patient's mouth and impedes the practitioner from achieving desired angles and restricts range of motion to effectively file. Especially when the patient is receiving crowns, bridges, onlays, or inlays in the back of the mouth where it is considerably more difficult to access, it is difficult for the practitioner to file since both hands are needed to hold tension in the strip and often a patient's mouth is too small or cannot open wide enough to accommodate the file comfortably. As a result, the patient must endure strenuous stretching of the lips and jaw area. Often a practitioner struggles to find the best placement for fingers to pinch the strip to create sufficient tension while attempting to minimize the restricting presence of both hands in the patient's mouth. This method is inefficient, tiresome for the practitioner, and uncomfortable for the patient. Moreover, because of the difficulty involved handling the filing strip, often patients sustain suffer small cuts due to the sharp edges of the strip coming in contact with gums and lips while filing the tooth or restoration.
Another method employed is that a thin metal strip coated with fine abrasive material is fastened to a removable bow which is attached a handle. Generally, the bow and handle are too long to maneuver in the mouth and limit the size of abrasive strip which is actual working surface and results ineffective in the mouth for posterior teeth. Replacing the filing strip after each use is also a hassle for the dental staff due to the fact that disassembly and assembly involve extremely small fasteners and tools. Compression on the ends of the bows will tend to loosen and pop off removable filing strips.
In order to solve the existing problems with the current methods for interproximal grinding and adjustment between restorations and teeth, it is the object of the present invention to provide a tool which has a body that secures a filing strip with sufficient tension which can be held by one hand between opposable fingers. This allows for the practitioner to maneuver within the patient's mouth with easier reach and greater range of motion for more time efficient and effective filing and grinding of the interproximal area with greater comfort for the patient for a quicker fitting of crowns, bridges, onlays, and inlays.
In addition to these inefficiencies many areas of the world lack high technology powered dental equipment and extensive training for dentists and dental assistants. Thus, the process of using powered tools to shape reconstructions out of the mouth are often not available, and such dentists are in need of an inexpensive, safe and reliable means of filing restorations and fillings in-situ.
A number of devices have provided abrasive surfaces for filing crowns, but lack the safety, control and ease of manufacture of the present invention. None of the known body of art, taken either singularly or in combination, is seen to describe the instant invention as claimed.
U.S. Pat. No. 6,386,873 to Blank teaches a filing tool with a Y-shaped handle with bosses on the ends to hold a filing blade, which is mounted by squeezing together the handle ends to hang the blade on the bosses through mounting holes. Blank does not teach a filing strip which is integrally mounted to a handle. Blank teaches a device which purports to be ergonomic for the user, which is an improvement to a degree. However, the user has to grasp the Blank device at the prongs in order to exert sufficient lateral force to be useful. Grasping Blank at the prongs would naturally tend to compress them together, creating a serious danger that the blade would separate. In addition, comparing the handle length required to form the Y-shape and provide the extended portion intended for gripping (see Blank, FIG. 1, #22), the Blank apparatus is actually quite large and clumsy for use inside a patient's mouth.
U.S. Pat. No. 2,730,804 to Saupe teaches a dental filing tool which uses a replaceable filing blade which slides into a jointed holder. The filing blade is gripped only along one side and not held in tension in the axis of the working surface. This limits the amount of lateral pressure which can be applied, and creates a danger where if the filing blade was used in a tight-fitting area the blade would either displace or bend. Saupe does not teach tapering and rounding the inner edges of the blade holder to allow the blade handle to fit comfortably against the gap between teeth without causing damage.
Japan Patent 593138377 (the JP '377 patent) teaches a dental filing tool with a U-shaped handle and filing strip. However, JP '377 teaches a replaceable filing strip mounted on pegs or bosses, rather than an embedded strip (see JP '377, FIGS. 3 and 7, #7). There is therefore a significant danger that the blade could separate during use in a patient's mouth. Applying lateral or longitudinal pressure during use naturally causes the user to squeeze the handle together which would loosen the blade and likely cause it to pop off. In addition, if the filing strip hit a difficult or tight area there is substantial risk that it might simply deform and tear off the pegs. This danger could be lessened by angling the pegs (#7) away from each other, but this would make assembly by dental staff very difficult, especially considering the small size of the parts. Nor does JP '377 disclose tapered inner edges to better fit within the facial and lingual embrasures between adjacent teeth, nor integral fingerpads for gripping.
Injection molding provides the ability to manufacture filing tools with non-removable filint strips so as to avoid danger of separation due to poorly designed or poorly assembled blade retention means. One can also thereby manufacture filing tools with tension built into the abrasive strip. Injection mold manufacturing techniques reduce cost sufficiently that the dental filing tools may be considered disposable. Disposing of the tools for recycling of the plastic and metal, rather than requiring dental staff to disassemble and replace abrasive strips, saves significant labor and supervision burdens, and prevents mistakes in assembly from causing harm to patients. The present invention solves these problems.
Thus, while the foregoing body of art indicates it to be well known to have a dental filing tool, the known art does not teach or suggest a dental filing tool which has the following combination of desirable features: (1) small enough to be held between two fingers by the user; (2) able to hold a filing strip securely without risk of separating in a patient's mouth; (3) inexpensively produced so as to be essentially disposable; (4) tensioned so as to be rigid enough to permit lateral pressure during both forward and reverse movement but still flexible so as to conform to concave/convex surfaces in the interproximal areas of teeth; (5) allows for easy and effective disinfection; and, (6) allows for easy and simplified labelling and indexing of filing blades; (7) tapered inner edges for comfortable fit into the facial and lingual embrasures; (8) includes integral fingerpads for easier control and efficient manufacture.